Computation of axisymmetric jet flow with Spalart-Allmaras turbulence model

A computational study for axisymmetric jet flow with Spalart-Allmaras turbulence model was carried out. The second order finite volume method, fine unstructured grids and non-reflecting boundary condition were used in solving the compressible N-S equations. The numerical results are in good agreement with experimental data. It is demonstrated that the Spalart-Allmaras turbulence model is suitable for numerical simulation of the axisymmetric jet flow and the sufficiently fine unstructured grids are helpful in obtaining the flow field details. In addition, it is found that, for under-expanded jet flow, computation should be started from the internal upstream of the nozzle exit and its exit boundary conditioned should not be prescribed as sonic profile in this case. It is useful in understanding nozzle internal and external flow field and impinging jet parameter distribution. It is also helpful for optimal design of nozzle internal structure.